Solar Energy Succeeds… Even in the Toilet!

September 3rd, 2012by Sara Pernas

A solar-powered toilet that generates hydrogen and electricity designed by California Institute of Technology in the United States won the first prize in Reinvent the Toilet, a competition for next-generation toilets to improve sanitation in the developing world, carried out by Bill & Melinda Gates Foundation.

Only 63% of the world population can access to safe, affordable and improved sanitation, opposite to around 2.6 billion people that do not have it. The main purpose of this charitable organisation is finding more affordable and affective loos that can be used by everybody all around the world.

A total of 28 designs shown off in the competition, that challenged participants to come up with a toilet that operated without running water, electricity or a septic system, running at a cost of no more than 3p per day and would ideally capture energy or other resources.

The winner project consists of a toilet that uses the sun to power an electrochemical reactor. The reactor breaks down water and human waste into fertilizer and hydrogen, which can be stored in hydrogen fuel cells as energy. The treated water can then be reused to flush the toilet or for irrigation.

The team had developed similar technology for Nasa, but it was not until the Foundation’s challenge came about that it was applied in this way.

Credit: Caltech/Michael Hoffmann / The Caltech team in front of the toilet system